JP2002200673A - Heat-shrinkable polyester tube for coating capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-shrinkable polyester tube for coating an electrolytic capacitor for protection and electric insulation and a method for producing the tube. SOLUTION: The heat-shrinkable polyester tube contains a polyester resin or copolyester resin as main components and 0.01-3 wt.% of external particles 0.5-3.5 μm in average particle size and has a slippage value of 300-800 g.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester-based heat-shrinkable tube for coating a capacitor and a method for manufacturing the same, and more particularly, to a polyester-based heat-shrinkable tube which is coated for protection of an electrolytic capacitor and electrical insulation. The present invention relates to a conductive tube and a method for manufacturing the same.

[0002]

2. Description of the Related Art In general, a heat-shrinkable tube is used for protecting a electrolytic capacitor and for covering a capacitor for electrical insulation, and the conventional heat-shrinkable tube is made of a synthetic resin, polyvinyl chloride resin (PVC). Have been.

Hereinafter, an application example of a heat-shrinkable tube will be described. Cover the electrolytic capacitor with heat-shrinkable tubing 230
After heating and shrinking at ~ 250 ° C for 2 ~ 3 seconds, it is washed with water at 70 ~ 80 ° C, and is subjected to dry heat treatment at 160 ° C for about 3 minutes in parallel with drying and heat resistance test before use. As a test of the coating film, a pinhole test and a drop test are performed.

As described above, a heat-shrinkable tube made of a polyvinyl chloride resin is generally used for coating an electrolytic capacitor. However, the polyvinyl chloride resin has a low heat resistance and strength, and is subjected to a dry heat treatment after a pinhole test. This makes it easier to tear, and not only does the product have a poor condition, but also has a low pass rate in the drop test. Therefore, it has been required to cover the electrolytic capacitor with a resin having excellent heat resistance and strength. In addition, polyvinyl chloride resin is not recyclable, and dioxane is generated during incineration, which seriously affects the natural environment. Is being done.

As a part of such research, Japanese Patent Publication No. 1974-32972 discloses that a polyester resin is used as a shrinkable tube for a capacitor, the capacitor is covered, shrunk, and then subjected to a dry heat treatment. It is disclosed that a heat-shrinkable tube excellent in electrical insulation and having excellent electrical insulation properties can be obtained by completely adhering to a capacitor.

On the other hand, when the heat-shrinkable tube is coated on the capacitor, the heat-shrinkable tube covers the upper surface and the lower surface of the capacitor when shrinking, and adheres to the bent portion of the side portion of the capacitor. Such adhesion causes deformation of the coated tube in a high-temperature washing step and a drying step performed after the step of coating and shrinking the capacitor. A resin composition for ensuring such adhesion performance is disclosed in Korean Patent Application No. 2000-2.
No. 686.

[0007]

However, in the recent step of coating a heat-shrinkable tube with a capacitor, the slip property between the heat-shrinkable tube and the capacitor is important during high-speed coating. By increasing the slip property of the tube,
In the high speed coating process, the tube can be coated on the capacitor without adhering to the surface of the capacitor.

For this reason, the present inventors have found that the present inventors have excellent slip properties and can apply a high-speed coating process to a capacitor. Attempts to manufacture a polyester heat-shrinkable tube with excellent electrical insulation as well as protection of the capacitor, and by adding external particles with an average particle size of 0.5 to 3.5 μm to have a certain range of slip properties As a result, the present invention meeting the above-mentioned requirements has been completed.

An object of the present invention is to provide an excellent slip property and to be applicable to a high-speed coating process of a capacitor, and to completely adhere to a component portion of a capacitor even during a dry heat treatment after coating and shrinking the capacitor. Another object of the present invention is to provide a polyester-based heat-shrinkable tube which protects a capacitor and has excellent electric insulation.

[0010]

Means for Solving the Problems (1) In order to achieve the above object, the polyester-based heat-shrinkable tube for coating a capacitor of the present invention contains a polyester resin or a copolymerized polyester resin as a main component and has an average particle size of 0.5. ~ 3.5μm
Is contained in an amount of from 0.01 to 3% by weight, and the value thereof is from 300 to 800 g when the slip property is measured.

(2) The polyester-based heat-shrinkable tube for coating a capacitor as described above, wherein the external particles are talc or silica.

(3) The polyester resin or copolymerized polyester resin is a copolymer resin comprising 1 to 15 mol% of polyethylene naphthalate and 85 to 99 mol% of polyethylene terephthalate and having an intrinsic viscosity of 0.65 to 1.0 dl / g. The polyester-based heat-shrinkable tube for coating a capacitor as described above, which is characterized in that:

(4) The polyester resin or the copolymerized polyester resin is 1 to 15 mol% of polyethylene naphthalate.
And 85-99 mol% of polyethylene terephthalate,
80 to 99% by weight of a copolymer resin having an intrinsic viscosity of 0.65 to 1.0 dl / g, and a resin obtained by melt-mixing polybutylene terephthalate and a pigment with 1 to 20% by weight, characterized in that it is a mixed resin. The polyester-based heat-shrinkable tube for coating a capacitor described above.

(5) The polyester resin or the copolymerized polyester resin is composed of 1 to 15 mol% of polyethylene naphthalate and 85 to 99 mol% of polyethylene terephthalate, and is a copolymer resin 80 to 99 having an intrinsic viscosity of 0.65 to 1.0 dl / g. % By weight, a resin obtained by melt-mixing polybutylene terephthalate and a pigment 1 to 20% by weight, and a resin comprising a metal salt of benzoic acid or stearic acid 0.01 to 1.0% by weight. The polyester-based heat-shrinkable tube for coating a capacitor according to the above.

[0015]

Embodiments of the present invention will be described below in detail.

The thermoplastic polyester resin constituting the heat-shrinkable tube of the present invention is not only polyethylene terephthalate containing terephthalic acid as an acid and ethylene glycol as a diol, but also isophthalic acid mixed with a large amount of terephthalic acid as an acid. , Copolymers having dicarboxylic acids such as naphthalene dicarboxylate, diphenoxyethane dicarboxylate, diphenyl dicarboxylate, diphenyl dicarboxylate, propane diol mixed with ethylene glycol as diol, butane diol, pentane diol, hexane diol, neo Copolymers with pentyl glycol, polyethylene glycol or blends of such polyesters.

Among them, preferred polyester resins are copolymerized polyester resins containing 1 to 15 mol% of an ethylene naphthalate component and 85 to 99 mol% of an ethylene terephthalate component by copolymerization, and have an intrinsic viscosity of 0.65%. ~ 1.
0 dl / g copolymer resin.

Such a copolymerized polyester resin may be used alone, but a resin obtained by melt-mixing 80 to 99% by weight of the copolymerized polyester resin with polybutylene terephthalate and a pigment is 1 to 20% by weight. Compositions can also be used.

Here, the copolymerized polyester resin comprising 1 to 15 mol% of an ethylene naphthalate component and 85 to 99 mol% of an ethylene terephthalate component is obtained by copolymerizing a predetermined amount of dimethyl ester of naphthalene dicarboxylate. It is also possible to mix an acid polyethylene copolymer with a polyethylene terephthalate resin and use a mixture containing 1 to 15 mol% of ethylene naphthalate as a copolymerization component of the mixture.

The ethylene naphthalate copolymer component is preferably 1 to 15 mol%, which is a ratio at which the obtained polyethylene terephthalate polymer exhibits appropriate crystallinity and can be easily formed into a tube. is there.

If the ethylene terephthalate copolymerization component is less than 1 mol%, it is difficult to form a tube, and if it exceeds 15 mol%, the resulting polyester-based heat-shrinkable tube has a large decrease in crystallization and heat resistance. Is undesirably reduced.

The copolymerized polyethylene terephthalate copolymer containing the ethylene naphthalate copolymer component can be easily produced based on a usual method for producing a polyethylene terephthalate resin. That is, when producing a polyester obtained by reacting terephthalic acid or its ester-forming derivative with ethylene glycol or its ester-forming derivative, 1-15 mol% of the acid is replaced by naphthalene carboxylate or its ester-forming derivative. It is possible.

The molecular weight of such a copolymer resin of polyethylene naphthalate and polyethylene terephthalate has an intrinsic viscosity.
When it is 0.65 or more, good mechanical properties are exhibited, so that it is suitable. However, when the intrinsic viscosity is 1.0 or more, it is impossible to form a thin film of 150 μm or less, and the intrinsic viscosity is preferably 0.65 to 1.0.

Further, external particles are added to the heat-shrinkable tube of the present invention in order to secure the slip property. The external particles form protrusions on the surface of the tube to provide slip properties between the tube and the condenser. Examples of the external particles include inorganic particles such as calcium carbonate, talc, clay, mica, aluminum silicate, silica, calcium metasilicate, and aluminum hydroxide, and organic particles such as Teflon (registered trademark) powder. It is also possible to use two or more together, but silica and talc are preferred.

Since the addition of external particles changes the crystallinity of the tube and affects the physical properties of the tube such as adhesion and dry heat resistance, the size and degree of dispersion of the external particles and their content are important. It is.

It is appropriate that the size of the external particles is 0.5 to 3.5 μm. If the size is smaller than 0.5 μm, the particle size is too small to obtain a proper level of slip property. If it is larger than this, the degree of dispersion is poor and the slip property is reduced.

When the content of the external particles is 0.01 to 3% by weight, excellent adhesion and dry heat resistance are exhibited. When the content of the external particles exceeds 3% by weight, the crystallinity of the tube rapidly increases, so that it is difficult to obtain shrinkage characteristics, and the adhesion to the tube decreases.

The evaluation of the slip property was measured using a slip property tester. The slip property tester was obtained by installing an auxiliary mechanism in a push-pull scale device.

If necessary, additives such as stabilizers, pigments, dyes, clays, lubricants and flame retardants may be mixed with the polyethylene terephthalate copolymer resin of the present invention to produce a heat-shrinkable tube. it can.

On the other hand, when a polybutylene terephthalate resin in which a pigment is added to the copolymer resin is added, the crystallization rate of the entire resin composition is adjusted to facilitate the processability, and the heat-shrinkable tube is connected to the capacitor. 170 ° C after shrinking the coating
When the dry heat treatment is performed for 3 minutes, it is possible to give characteristics that substantially no voids are formed in the components of the capacitor. When a polybutylene terephthalate resin containing a pigment is added to such a copolymer resin, the amount added is preferably about 1 to 20% by weight. If the addition amount is less than 1% by weight, there is no effect on the crystallization rate control, and if it exceeds 20% by weight, the crystallization rate sharply increases and it becomes difficult to form a stretched tube. The amount of the pigment contained in the polybutylene terephthalate resin is preferably about 10 to 30% by weight.

The heat-shrinkable tube composition of the present invention may further contain 0.01 to 1.0% by weight of a metal salt of benzoic acid or stearic acid for finely controlling the crystallization rate. By adding a metal salt of benzoic acid or stearic acid, the crystallization rate can be appropriately changed depending on the size of the capacitor to be coated, and the heat resistance can be increased.

On the other hand, 1 to 5 polyester elastomers
It can also be supplemented by weight percent to complement flexibility and adhesion.

Hereinafter, a method for producing the polyester heat-shrinkable tube according to the present invention will be described.

A heat-shrinkable tube is produced from a copolymerized polyethylene terephthalate copolymer resin containing an ethylene naphthalate copolymer component by forming a tubular body by melt extrusion by a molding method such as a tube method or an inflation method. A method of axial stretching is used. At this time, the external particles can be added at the time of polymerization of the copolymer resin, or a method of extruding by mixing a compounding or polymer resin and a copolymer resin produced so as to contain a certain amount of the external particles, and extruding the external particles. Any of the methods of directly mixing and extruding with a copolymer resin may be used.

As an example of a tube production method, the copolymer composition is extruded from an annular base of an extruder to obtain an unstretched tubular body, and the tubular body is quenched in a cooling tank and then cooled. At the same time as heating at a temperature equal to or higher than the secondary transition temperature of the copolymer mixture and below the pour point, a compressed gas such as air and nitrogen is charged and expanded to expand in the diameter direction of the tubular body,
The heat-shrinkable tube is obtained by stretching using a differential speed roll or the like also in the longitudinal direction. This biaxial stretching may be carried out continuously with the extrusion of the tubular body, or may be carried out after winding it in a roll in an unstretched state. To produce an unstretched tubular body, the thickness of the heat-shrinkable tube after biaxial stretching is suitably in the range of 50 to 100 μm. An unequal shrinkage ratio of the shrinkable tube of 40-60% in the diameter direction and 5-15% in the longitudinal direction is appropriate. The stretching ratio can be achieved by appropriately selecting the stretching ratio in the range of 1.7 to 2.5 times and the stretching ratio in the longitudinal direction of 1 to 1.5 times.

As described above, according to the present invention, 1 to 15 mol% of polyethylene naphthalate and polyethylene terephthalate 85
80 to 99% by weight of a copolymer resin having an intrinsic viscosity of 0.65 to 1.0 dl / g, and 0.01 to 3% by weight of external particles such as silica or talc having an average particle diameter of 0.5 to 3.5 μm. A polyester-based heat-shrinkable tube for coating an electrolytic capacitor formed of a resin composition of 1 to 20% by weight of a resin obtained by melt-mixing an acid polybutylene and a pigment is manufactured, and the capacitor (length: 24 mm, outer diameter: 12.5%) 2mm to 5mm from the bottom as a condenser with a curved surface, the deepest part of which has a diameter of 11mm and is located 4mm from the bottom.) In the subsequent dry heat treatment (170 ° C. × 3 minutes), substantially no space is generated in the components of the capacitor. In addition, it shows excellent coating adhesion after a washing step of 100 ° C. water for 3 minutes.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the examples.

[0038]

EXAMPLES Example 1 PET containing 0.5% by weight of talc having an average particle size of 2 μm and copolymerized with 5% by mole of dimethyl ester of naphthalene dicarboxylate dried at 150 ° C. for 6 hours by a hot air circulating dryer. 95.4% by weight of copolymer (intrinsic viscosity 0.88)
And a polybutylene terephthalate resin containing 30% by weight of a pigment
A cylinder temperature of 220 to 280 ° C. from an extruder in which an annular base was installed by mixing 2.5% by weight, sodium salt of stearic acid 0.1% by weight, and 2% by weight of a polyester elastomer,
A tubular body having an outer diameter of 7 mm and a thickness of 150 μm was extruded at a table temperature of 260 ° C., cooled in a water bath at 40 ° C., and wound around a roll.

Inject 0.7 kg / cm ² of compressed air into the end of the obtained tubular body and heat it with hot water at 90 ° C. to expand it and simultaneously stretch it in the longitudinal direction by applying tension in the longitudinal direction using a differential speed roll. Magnification 1.05, diametric stretching ratio 2.0,
Simultaneous biaxial stretching was performed at a stretching speed of 10 m / min.

The obtained heat-shrinkable tube had an inner diameter of 13.3 mm,
The thickness was 75 μm, the shrinkage in the diameter direction was 48%, and the shrinkage in the longitudinal direction was 8%.

Examples 2 to 5 and Comparative Examples 1 to 5 A heat-shrinkable tube was produced in the same manner as in Example 1 except that the composition and the processing conditions were as shown in Table 1 below. changed.

[0042]

[Table 1]

[Experimental Examples] The above Examples 1 to 5 and Comparative Examples 1 to
The heat shrinkable tube obtained according to 5 was evaluated by the following method.

(1) Slip property: Measured by a slip property tester, which is a push-pull scale device provided with an auxiliary mechanism. Slip property measured 30
When it was 0 to 800 g, application to high-speed coating was possible. The slip property measurement value is preferably in the range of 400 to 700 g.

(2) Coating adhesion: The obtained heat-shrinkable tube was coated on a capacitor having a diameter of 12.5 mm, and was heated at 260 to 280 ° C. for 8 hours.
The capacitor was shrunk by heat treatment for 2 seconds to obtain a capacitor in which the tube was completely adhered. ｛O: Perfectly adhered to the outer wall of the capacitor｝ ｛X: Irregularities occurred without completely adhered to the outer wall of the capacitor｝

(3) Hot water heat resistance: The obtained heat-shrinkable tube was covered with a condenser having a diameter of 12.5 mm and heat-treated and shrunk at 260 to 280 ° C. for 8 seconds. It was treated with hot water at 2 ° C for 10 minutes. ｛O: Perfectly adhered to the outer wall of the capacitor｝ ｛X: Irregularities occurred without completely adhered to the outer wall of the capacitor｝

(4) High temperature heat resistance: The obtained heat-shrinkable tube was covered with a 12.5 mm diameter capacitor and heated at 260-280 ° C. for 8 hours.
The capacitor was heat-treated and contracted for 2 seconds, and the capacitor with the tube completely adhered was subjected to dry heat treatment at 170 ± 5 ° C. for 3 minutes. ｛O: Perfectly adhered to the outer wall of the capacitor｝ ｛X: Irregularities occurred without completely adhered to the outer wall of the capacitor｝

[0048]

[Table 2]

The slip property was measured using a push-pull scale device shown in FIG. A heat-shrinkable tube to be measured is cut into a length of 40 cm, and a pilot bar 8 that matches the diameter of the cut tube 7 is selected. After the pilot bar 8 is inserted into the tube 7 so that the end of the tube 7 is aligned with the end 8 of the bar, the pilot bar 8 is attached to the chip 4 shown in the attached drawing. The sample adjusted in this manner is mounted on the path of the pilot bar, the guide guide rear stage 1, the tube stopper 2, and the guide guide front stage 3. At this time, when the pilot bar 8 is fixed to the tube stopper 2, it is attached so as not to affect the movement of the pilot bar 8. After mounting the sample, the slide 6 is moved in the gauge direction. When the slide 6 is moved, the tip (tip) 4 moves in the direction of the gauge 5,
At this time, the scale that appears on the gauge 5 is read. The scale that appears on the gauge 5 indicates the slip property of the sample, and its unit is k
gf.

In the measurement of the slip property, a value is obtained in the unit of kgf. By indexing this value, the value in the unit of g obtained in claim 1, table 2, etc. can be obtained.

The intrinsic viscosity is 60% phenol and 40%
Was adjusted to a concentration of 0.5 g / dl with a 30 ° C. constant temperature bath, and
de) Measured with a viscometer.

[0052]

As described above, according to the present invention, external particles are added to the polyethylene terephthalate copolymer resin in order to improve the slip property, and the pigment-containing polybutylene terephthalate resin, sodium stearate or elastomer is added thereto. The heat-shrinkable tube manufactured with the added composition has excellent slip properties and can be applied to the high-speed coating process on capacitors, improving work efficiency. And has excellent effects of protecting the capacitor and providing excellent electrical insulation.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a push-pull scale device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Guidance guide latter part 2 ... Tube stopper and transfer apparatus 3 ... Guidance guide former part 4 ... Tip 5 ... Gauge 6 ... Slide 7 ... Tube 8 ... Pilot bar

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) // B29K 67:00 B29K 67:00 105: 02 105: 02 B29L 7:00 B29L 7:00 (72) Inventor Junmyung Song South Korea Seoul-City Empyon-ku Sinsa-dong 37-14 (72) Inventor Yongseo Kim South Korea Gyeonggi-do Sengnam-City Bundang-Kuk Kumi-dong Kachimaerle Shinwon Apartment 311-1902 (72) Inventor Jong-min Park Republic of Korea Gwangju-City Gwangsan-Kwalgiye-Dong 757-7 Kumwan-Apartment 103-704 (72) Inventor Gyeong-Jung-South Korea Gwangju-City Gwangsan-C Gwangsan-Dong 1572-5 Dongsan-Apartment 103-609 F-term ( Reference) 4F210 AA24C AA24E AB16 AB17 AB19 AE01 AG01 AH33 RA03 RC02 RG02 RG04 RG43 4J002 CF041 CF061 DJ017 DJ047 FD096 GQ00

Claims (5)

[Claims] 1. A polyester resin or a copolymerized polyester resin as a main component, containing 0.01 to 3% by weight of external particles having an average particle size of 0.5 to 3.5 μm, and having a value of 300 to 800 g when measuring slip properties. A polyester-based heat-shrinkable tube for coating a capacitor. 2. The heat-shrinkable polyester-based tube for coating a capacitor according to claim 1, wherein the external particles are talc or silica. 3. The polyester resin or copolymerized polyester resin comprises 1 to 15 mol% of polyethylene naphthalate and 85 to 99 mol% of polyethylene terephthalate, and has an intrinsic viscosity of
The polyester-based heat-shrinkable tube for coating a capacitor according to claim 1, which is a copolymer resin of 0.65 to 1.0 dl / g. 4. The polyester resin or copolymerized polyester resin is composed of 1 to 15 mol% of polyethylene naphthalate and 85 to 99 mol% of polyethylene terephthalate, and 80 to 99 weight% of copolymer resin having an intrinsic viscosity of 0.65 to 1.0 dl / g. The polyester-based heat-shrinkable tube for coating a capacitor according to claim 1, wherein the mixed resin is a mixed resin of 1% to 20% by weight of a resin obtained by melt-mixing polybutylene terephthalate and a pigment. . 5. The polyester resin or copolymerized polyester resin comprises 1 to 15 mol% of polyethylene naphthalate and 85 to 99 mol% of polyethylene terephthalate, and has an intrinsic viscosity of
0.65-1.0 dl / g copolymer resin 80-99% by weight, resin 1-2 obtained by melt-mixing polybutylene terephthalate and pigment
0% by weight and a metal salt of benzoic acid or stearic acid 0.01
The polyester-based heat-shrinkable tube for coating a capacitor according to claim 1, wherein the heat-shrinkable resin-coated tube is a resin comprising 1.0 to 1.0% by weight.